1. Field of the Invention
The present invention relates to a control apparatus of a lamp used both as, for example, a stop lamp indicating braking of a vehicle and another lamp of, for example, a turn signal lamp or the like.
2. Description of Related Art
Conventionally, when a lamp is used both as a stop lamp and a turn signal lamp or the like in a vehicle, in order to give priority to a function of a lamp to be flashed, a circuit constitution as shown by FIG. 9 is adopted.
Here, there is provided a multifunction switch 50 comprising a plurality of change-over switches 62, 64 and 66 constituting a hazard switch 60 and a plurality of changeover switches 72, 74, 76 and 78 constituting a turn signal switch 70 and the hazard switch 60 is inputted with an output from a stop lamp switch 52 and an intermittent signal from a timing circuit 54.
The turn signal switch 70 is inputted with an output from the hazard switch 60 and the intermittent signal from the timing circuit 54. Further, an output side of the turn signal switch 70 is connected with respective left and right lamps 16L, 18L, 16R and 18R of front and rear.
In the case in which both of the hazard switch 60 and the turn signal switch 70 are made OFF (OFF), when a brake, not illustrated, is operated, the output from the stop lamp 52 continuously light the left and right lamps 18L and 18R of rear from the change-over switch 62 via the change-over switches 76 and 78.
When the hazard switch 60 is made ON (ON) under the state, the output from the stop lamp switch 52 is cut by the change-over switch 62, the intermittent signal from the timing circuit 54 intermittently lights (hereinafter, flashes) the left and right lamps 16L and 16R of front from the change-over switches 64 and 66 of the hazard switch via the change-over switches 72 and 74 and flashes the left and right lamps 18L and 18R of rear from the change-over switch 62 via the change-over switches 76 and 78.
When the hazard switch 60 and the stop lamp switch 52 are made OFF and the turn signal switch 70 is made ON to left or right direction, the intermittent signal from the timing circuit 54 flashes the left lamps 16L and 18L of front and rear or the right lamps 16R and 18R via the change-over switches 72 and 74.
Further, when the brake is operated during the time period, a signal from the stop lamp switch 52 continuously light the lamp of rear on a side of not flashing from the change-over switch 62 via the change-over switches 76 and 78 of the turn signal switch 70.
However, according to the above-described conventional circuit constitution, inside the multifunction switch 50, there are needed an extremely large number of the change-over switches each having a mechanical contact related to conduction of large current supplied to the lamps as the turn signal switch 70 and the hazard switch 60. According to the change-over switch having such a mechanical contact, not only the cost is high but also a difficulty is accompanied in ensuring durability. Further, there poses a problem that emittance of operating sound is unavoidable.
Although as a countermeasure thereagainst, it is conceivable to replace the change-over switch to a circuit of a logical element which is not provided with a mechanical contact, since large current is dealt with, simple replacement cannot be carried out.